diff -r 0053aa3d8c22 -r e66fc1287031 src/devices/wifi/dcf-manager.cc
--- a/src/devices/wifi/dcf-manager.cc	Fri Jun 26 13:58:03 2009 +0200
+++ b/src/devices/wifi/dcf-manager.cc	Fri Jun 26 15:25:51 2009 +0200
@@ -577,7 +577,7 @@
     //this may be caused only if PHY has started to receive a packet
     //inside SIFS, so, we check that lastRxStart was maximum a SIFS
     //ago
-    NS_ASSERT(Simulator::Now () - m_lastRxStart < m_sifs);
+    NS_ASSERT(Simulator::Now () - m_lastRxStart <= m_sifs);
     m_lastRxEnd = Simulator::Now ();
     m_lastRxDuration = m_lastRxEnd - m_lastRxStart;
     m_lastRxReceivedOk = true;